Maggie Barbieri won't go kayaking on the Croton River without a hat, sunglasses, a UV-protectant shirt and a careful application of sunscreen.

Barbieri, a Blauvelt native who lives in Croton-on-Hudson, wasn't always as vigilant about sun protection. As a teenager she spent summers baking on the beach, and believes it was one blistering sunburn at the Jersey Shore that contributed to her being diagnosed with melanoma in 2005, at the age of 41.

One year later, the cancer had spread throughout her body. It wasn't clear whether she would survive.

These days, the dangers of the sun are well-documented: According to the Skin Cancer Foundation, about 86 percent of melanomas are caused by exposure to ultraviolet radiation from the sun. The American Cancer Society estimates that more than 9,700 people will die of melanoma in 2014.

Basal-cell and squamous-cell carcinomas, the less serious forms of skin cancer, are also tied to sun exposure. It is estimated that 1 in 5 Americans will develop some form of skin cancer in their lifetime. All races and ethnicities can get skin cancer, but light-eyed, fair-skinned people are most at risk.

In late May, the FDA changed its regulations on tanning beds and booths, requiring them to carry a black-box warning recommending against their use for people under 18 — a move championed by the Melanoma Research Foundation. The change was motivated by increasing awareness of the dangers of UV radiation, and studies attributing the rising rates of melanoma in young people to the use of tanning devices.

The FDA also recently changed its requirements for sunscreens, mandating that products labeled "broad spectrum" pass a test that proves their effectiveness. In addition, packaging can no longer claim a sunscreen is "waterproof." Products that have SPFs lower than 15 must carry a warning stating they are not shown to protect against skin cancer and early skin aging.

The sun's damaging rays

Even if you never go to a tanning salon, the sun remains a major factor in the development of skin cancer.

"During the summer months, if you think you're going to be out for any period at all, put on sunscreen first thing in the morning," says Rye Brook dermatologist Dr. Andrew Bronin, associate clinical professor of dermatology at Yale School of Medicine and editor-in-chief of the American Academy of Dermatology's "DERMCLIPS: Current Literature in Perspective."

"Just one bad burn is enough to significantly increase your risk of melanoma," he said.

Even if you stay out of the sun between 10 a.m. and 2 p.m., you are still exposed to radiation from UVA rays. And the danger is year-round — which means sunscreen makes sense even in the colder months.

"UVB burns you," says Bronin. "UVA does just as much or more damage to your skin, but it doesn't let you know. It does the damage insidiously."

Dr. Wendy Epstein, a West Nyack dermatologist and adjunct assistant professor of dermatology at NYU School of Medicine, frequently sees patients with skin cancers, and pre-skin cancers, on the left side of the face, presumably caused by sun exposure while driving. UVA rays, but not UVB, are capable of penetrating glass, she says, which makes a UV-blocking film an important add-on to driver's side car windows.

The sun also ages the skin, says Epstein, a medical and cosmetic dermatologist. "The damage is like leaving rubber bands out in the sun — they become brittle," she says. "The elastic fibers in our skin become destroyed and there's a decrease in collagen. That's a direct consequence of chronic UV exposure."

Staying safe

The belief that people get 80 percent of their "ultraviolet dose" by the age of 18 is simply untrue, says Bronin: Sun exposure continues to have a negative impact on the skin throughout one's lifetime.

Doctors recommend staying in the shade when the sun is at its most intense, using a water-resistant broad-spectrum sunscreen and wearing a wide-brimmed hat. Sun-protective clothing, made from fabrics that block UV rays, offers additional protection. So do umbrellas.

Epstein, a dermatologist for more than 25 years, wore sun-protective outfits long before they became popular. "My daughter wrote her college essay on the sun-phobia disease that her mother had," she says, noting that her own grandmother used a parasol — and that her daughter, now in her twenties, has realized the importance of sun safety. "You can say all you want to your kids, but if you do it yourself, they will eventually follow suit."

Bronin wears a broad-spectrum sunscreen with an SPF of 60, and adds a hat and a long-sleeved shirt if he's going to be sitting somewhere like a baseball stadium. "Not taking prudent precautions against the possible damaging rays of the sun is as silly as smoking," he says. "There's no reason people can't enjoy being outside, but they have to practice 'safe sun.' "

The American Academy of Dermatology recommends regular skin self-exams to check for signs of skin cancer — studies have found that more than 60 percent of melanomas are initially found by patients checking their own skin for irregularities — and getting full-body exams from a dermatologist.

But for Maggie Barbieri, there was no early warning sign that she might have skin cancer. When she went to the doctor nine years ago with a lump in her groin, a biopsy showed it was a melanoma tumor. Chemotherapy, surgery and radiation seemed to have gotten rid of the cancer — but two months after she finished treatment, Barbieri learned the melanoma had spread, eventually becoming a Stage IV diagnosis.

"When you hear melanoma, a lot of people think, 'Oh it's just skin cancer,' " she says. "It isn't just skin cancer. It's deadly and it's insidious and it can spread. I had tumors on my liver."

Dr. Anna Pavlick, a melanoma specialist at NYU Langone Medical Center, enrolled Barbieri in the clinical trial of an immunotherapy drug that saved her life. This past February, she marked five years of being cancer-free.

"I truly believe the damage I did to my skin in my teens contributed to my melanoma diagnosis as an adult," says Barbieri, whose 15-year-old son and 20-year-old daughter are well-versed in the importance of sun protection.

"My doctor and I both believe you start with the children. I'm looking forward to the day when all of our kids don't dream of going outside without wearing a hat and sunscreen."

Dr. Peter Richel, chief of pediatrics at Northern Westchester Hospital in Mount Kisco, grew up surfing in south Florida, where he remembers sun worshipers hitting the beach with aluminum reflectors. Kids and parents need to understand the serious risks of sun exposure, says Richel, whose guidelines include the following:

• Don't let the clouds fool you. You can get just as much sun exposure and risk on a cloudy day.

• Use a sunblock that screens UVA and UVB rays, with an SPF of at least 30. Be sure to apply to the shoulders, and the tops of the ears and feet.

• Apply sunscreen 30 minutes before exposure, and reapply hourly, particularly after getting wet. Even if a product is marketed as a "sports sunscreen,'' it's still important to reapply it. Good choices include Blue Lizard Australian Sunscreen and Banana Boat for kids.

• Watch for skin reactions. Sometimes, children with sensitive skin can get a rash from a sunscreen. To make sure the rash isn't sun poisoning, check with your pediatrician.

• Shade is the best sunscreen for infants. But, in accordance with recommendations from the American Academy of Pediatrics, he says it's OK for babies under six months old to have small amounts of sunscreen on exposed areas if they are in a wading pool with parents or caregivers.

• Floppy hats and sunglasses are a good idea for children.

• If a child gets a bad sunburn, with blistering skin, it's important to see your pediatrician for treatment.

Melanoma: a deadly form of skin cancer

According to the American Cancer Society, rates of melanoma have been rising steadily for the past 30 years.

"The increased number of melanomas is bad news, but the increased percentage of early melanomas is good news, because the earlier you catch it, the better the prognosis," says Rye Brook dermatologist Dr. Andrew Bronin, associate clinical professor of dermatology at Yale School of Medicine.

When a melanoma is identified on the body, the aim is to remove the growth when it is still confined to the epidermis, or upper layer of the skin, which has no blood vessels and no lymph vessels, says Bronin.

Best described as a "funny looking mole," a melanoma is often dark or has variations in color. The American Academy of Dermatology's "ABCDEs of melanoma" is a set of guidelines aimed at helping people identify suspicious moles. Look for:

A: Assymetry (one half is unlike the other half)

B: Border (an irregular, scalloped or poorly defined border)

C: Color (varied from one area to the other)

D: Diameter (melanomas are usually greater than the size of a pencil eraser when diagnosed, but can be smaller)

E: Evolving (a mole or lesion that looks different, or is changing in size, shape or color)

"The danger that melanoma poses is that it can spread to other organs, or metastasize — which is how any cancer does its damage — and eventually kill you," says Bronin. "The goal is to remove the melanoma completely before it ever has the opportunity to do that. The melanoma can't spread when its depth is limited to the top layer of the skin, but it is eminently recognizable at that stage, and if it is totally excised at that stage, it is totally cured."

What the initials mean

SPF: Sun-protection factor, a measure of how much protection a sunscreen offers against UVB radiation. A product with an SPF of 15 blocks 14/15ths of the sun's rays, or about 93 percent; an SPF 30 sunscreen blocks out 29/30ths of the sun's rays, or 97 percent. You need to use about two tablespoons of sunscreen on the body to achieve a product's SPF.

UPF: Ultraviolet-protection factor, a rating used in sun-protective clothing.

UVB: Ultraviolet B rays, strongest between 10 a.m. and 4 p.m. They are generally the cause of sunburns.

UVA: Ultraviolet A rays, which penetrate more deeply into the skin and can cause serious damage, often without a visible burn. Tanning beds emit primarily UVA radiation, up to 12 times more than the sun. UVA rays can penetrate untreated car and other windows.

Protect your eyes, too

Ultraviolet rays are harmful to the eyes, and can lead to cataracts and macular degeneration later in life, says Dr. William Dieck, an opthalmologist in Mount Kisco. Dr. Wendy Epstein, a dermatologist in West Nyack, has also seen cases of skin cancer on the lower eyelid. Be sure to choose sunglasses that block UVA and UVB rays.

How sunscreens work

Sunscreens work in either of two ways. Chemical formulations — with active ingredients like avobenzone or Mexoryl — need to be absorbed into the skin in order to take effect. That's why it's essential to apply them 30 minutes before sun exposure. Physical blocks, like zinc oxide and titanium dioxide, reflect the sun's rays and are not absorbed into the skin.

Doctors say that some chemical sunscreens can cause skin irritation, but that physical blocks do not usually have the same effects. Be sure to choose a product that offers broad-spectrum protection, and reapply it frequently.

The Sunscreen Innovation Act, a bipartisan bill under review by Congress, would require the FDA to make rulings on sunscreen ingredients in a more timely fashion. The Public Access to SunScreens Coalition (PASS) has more information online.